Autotile corners problem

[jpx]

So I made a set of grass autotiles for a game I'm working on. They seem to be working properly, except when I put them in the editor, the top-right and top-left inner corners show up like this:

And here's the tileset. (Most of the tiles in here are dummies, as I'm far from finished making this tileset. My grass tiles can be seen toward the lower left.)

Does anyone know what to do about this problem? Is it a glitch in the editor, or is there something wrong with my tileset?

 

[Sharm]

It's not a glitch, it's displaying the inner corners exactly how you drew them.  I like to leave the inner corners for last.  I leave them blank and use the tile to draw a plus sign with them so I get a good easy view of the inner corners and how they'll interact with the edges.  Then I take a screencap and draw the inner corners on there then copy it into the tileset.  Usually it's good but I like to test it more thoroughly at that point to make absolutely sure that it'll work right.